# CVE-2023-53826: linux: In the Linux kernel, the following vulnerability has been resolved:  ubi: Fix UAF wear-leveling entry in eraseblk_cou...

CVE-2023-53826 is fixed in linux on 1 platform, first by DEBIAN-CVE-2023-53826, released December 9, 2025. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2023-53826
- Priority: Routine
- CVSS: n/a
- EPSS: 0.0025
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Dec 9, 2025

## Description

In the Linux kernel, the following vulnerability has been resolved:  ubi: Fix UAF wear-leveling entry in eraseblk_count_seq_show()  Wear-leveling entry could be freed in error path, which may be accessed again in eraseblk_count_seq_show(), for example:  __erase_worker                eraseblk_count_seq_show                                 wl = ubi->lookuptbl[*block_number] 				if (wl)   wl_entry_destroy     ubi->lookuptbl[e->pnum] = NULL     kmem_cache_free(ubi_wl_entry_slab, e) 		                   erase_count = wl->ec  // UAF!  Wear-leveling entry updating/accessing in ubi->lookuptbl should be protected by ubi->wl_lock, fix it by adding ubi->wl_lock to serialize wl entry accessing between wl_entry_destroy() and eraseblk_count_seq_show().  Fetch a reproducer in [Link].

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 12.15 (bookworm) | 6.1.20-1 | [DEBIAN-CVE-2023-53826](https://patchblox.com/security/data/fix/linux/debian-cve-2023-53826.md) | Dec 9, 2025 |
| Linux | linux Debian 13.5 (trixie) | 6.1.20-1 | [DEBIAN-CVE-2023-53826](https://patchblox.com/security/data/fix/linux/debian-cve-2023-53826.md) | Dec 9, 2025 |
| Linux | linux Debian 14 | 6.1.20-1 | [DEBIAN-CVE-2023-53826](https://patchblox.com/security/data/fix/linux/debian-cve-2023-53826.md) | Dec 9, 2025 |

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